Browse Prior Art Database

Ported Hot Gas Probe

IP.com Disclosure Number: IPCOM000108281D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 69K

Publishing Venue

IBM

Related People

Davis, GA: AUTHOR

Abstract

This article describes a hot gas probe which is used to remove (unsolder) devices from substrates during rework of the substrates.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 86% of the total text.

Ported Hot Gas Probe

       This article describes a hot gas probe which is used to
remove (unsolder) devices from substrates during rework of the
substrates.

      In the existing technique an inert gas is pumped down the probe
through an electrical heater element.  The heated gas is directed
through a diffuser and on to the device to be removed.  When the
solder reflow temperature is reached, the gas is shut off and a
vacuum is applied through the heater element and the device is lifted
off the substrate. Shutting off gas flow through the heater element
and applying a vacuum through it is detrimental to the heater element
and shortens the heater element life.

      The probe disclosed herein is shown in front view in the
drawings.  A two-port barrel valve is designed into the probe.  In
operation heated gas is directed down through port #1 of the barrel
valve to the device (Fig. 1).  The hot gas is vented around the tip
of the probe through port #2 of the barrel valve.  This protects
adjacent devices from hot gas.  When proper device temperature is
reached the barrel valve is rotated 90~ and hot gas is directed away
from the device through port #1 and vented outside the probe through
the port #2 of the barrel valve (Fig. 2).  Power is removed from the
heating element and continuous gas flow is used to cool the element.

      Port #2 of the barrel valve seals off the exhaust ports around
the tip of the probe and a vacuum is applied and the probe...